convert margin to S7

Author: teunbrand

DESCRIPTION

@@ -177,6 +177,7 @@ Collate:
     'grob-null.R'
     'grouping.R'
     'properties.R'
+    'margins.R'
     'theme-elements.R'
     'guide-.R'
     'guide-axis.R'
@@ -201,7 +202,6 @@ Collate:
     'layer-sf.R'
     'layout.R'
     'limits.R'
-    'margins.R'
     'performance.R'
     'plot-build.R'
     'plot-construction.R'

R/geom-label.R

@@ -87,7 +87,7 @@ GeomLabel <- ggproto("GeomLabel", Geom,
     data <- coord$transform(data, panel_params)
     data$vjust <- compute_just(data$vjust, data$y, data$x, data$angle)
     data$hjust <- compute_just(data$hjust, data$x, data$y, data$angle)
-    if (!is.margin("margin")) {
+    if (!is.margin(label.padding)) {
       label.padding <- rep(label.padding, length.out = 4)
     }
 

R/guide-legend.R

@@ -697,7 +697,9 @@ position_margin <- function(position, margin = NULL, gap = unit(0, "pt")) {
     left   = replace(margin, 2, margin[2] + gap),
     right  = replace(margin, 4, margin[4] + gap)
   )
-  class(margin) <- union("margin", class(margin))
+  # We have to manually reconstitute the class because the 'simpleUnit' class
+  # might be dropped by the replacement operation.
+  class(margin) <- c("ggplot2::margin", class(margin), "S7_object")
   margin
 }
 

R/margins.R

@@ -1,13 +1,23 @@
+#' @include properties.R
+
 #' @param t,r,b,l Dimensions of each margin. (To remember order, think trouble).
 #' @param unit Default units of dimensions. Defaults to "pt" so it
 #'   can be most easily scaled with the text.
 #' @rdname element
 #' @export
-margin <- function(t = 0, r = 0, b = 0, l = 0, unit = "pt") {
-  u <- unit(c(t, r, b, l), unit)
-  class(u) <- c("margin", class(u))
-  u
-}
+margin <- S7::new_class(
+  "margin", parent = S7::new_S3_class(c("simpleUnit", "unit", "unit_v2")),
+  constructor = function(t = 0, r = 0, b = 0, l = 0, unit = "pt") {
+    u <- unit(c(t, r, b, l), unit)
+    S7::new_object(u)
+  },
+  properties = list(
+    top    = property_index(1L),
+    right  = property_index(2L),
+    bottom = property_index(3L),
+    left   = property_index(4L)
+  )
+)
 
 #' @rdname element
 #' @export
@@ -23,7 +33,7 @@ margin_auto <- function(t = 0, r = t, b = t, l = r, unit = "pt") {
 
 #' @export
 #' @rdname is_tests
-is.margin <- function(x) inherits(x, "margin")
+is.margin <- function(x) S7::S7_inherits(x, margin)
 
 #' Create a text grob with the proper location and margins
 #'

R/properties.R

@@ -43,3 +43,16 @@ property_nullable <- function(class = S7::class_any, ...) {
     ...
   )
 }
+
+property_index <- function(i) {
+  force(i)
+  S7::new_property(
+    getter = function(self) {
+      self[i]
+    },
+    setter = function(self, value) {
+      self[i] <- value
+      self
+    }
+  )
+}

R/theme-elements.R

@@ -87,8 +87,11 @@ element <- S7::new_class("element", abstract = TRUE)
 #' @rdname element
 element_blank <- S7::new_class("element_blank", parent = element)
 
+
 # All properties are listed here so they can easily be recycled in the different
 # element classes
+#' @include properties.R
+#' @include margins.R
 element_props <- list(
   fill       = property_nullable(S7::class_character | S7::new_S3_class("GridPattern") | S7::class_logical),
   colour     = property_nullable(S7::class_character | S7::class_logical),

R/theme.R

@@ -867,7 +867,7 @@ S7::method(merge_element, list(element, S7::class_any)) <-
     new
 }
 
-S7::method(merge_element, list(S7::new_S3_class("margin"), S7::class_any)) <-
+S7::method(merge_element, list(margin, S7::class_any)) <-
   function(new, old, ...) {
     if (is.null(old) || S7::S7_inherits(old, element_blank)) {
       return(new)
@@ -911,7 +911,7 @@ combine_elements <- function(e1, e2) {
     return(e1)
   }
 
-  if (inherits(e1, "margin") && inherits(e2, "margin")) {
+  if (is.margin(e1) && is.margin(e2)) {
     if (anyNA(e2)) {
       e2[is.na(e2)] <- unit(0, "pt")
     }
@@ -921,7 +921,7 @@ combine_elements <- function(e1, e2) {
   }
 
   # If neither of e1 or e2 are element_* objects, return e1
-  if (!S7::S7_inherits(e1, element) && !S7::S7_inherits(e2, element)) {
+  if (!is.theme_element(e1) && !is.theme_element(e2)) {
     return(e1)
   }
 
@@ -949,7 +949,7 @@ combine_elements <- function(e1, e2) {
     e1@linewidth <- e2@linewidth * unclass(e1@linewidth)
   }
 
-  if (inherits(e1, "element_text")) {
+  if (S7::S7_inherits(e1, element_text)) {
     e1@margin <- combine_elements(e1@margin, e2@margin)
   }